Knowing where your customers were before they showed up at your business, online or offline, while insightful, is not as important as knowing who they are, what they wanted on your site and if they found it. Over the last 18 months, business owners and social media strategists have started using social media platforms like Radian6 and Alterian/SM2-Techrigy to find audiences that will engage with your businesses or brands in the way you want them to.

However, the easiest and most inexpensive approach to finding the right audience for your business is locating influential bloggers who will spread the word virally and drive their blogs' audiences to a desired site using free tools like Technorati, which ranks blogs by authority. In some cases, the Google search engine, using specific search terms, can be used to collect lists of subject-relevant bloggers to contact. PR firms such as Abraham Harrison have built lists of several thousand bloggers, by subject and tag, to use for clients' campaigns, and anyone who has the time and inclination can employ the same approach, albeit on a smaller scale.

Some applications such as Dan Zarrella's ReTweetability Index use Twitter's interface to pull out the most influential Twitter accounts by keyword and number of re-tweets, who has been re-tweeted the most times, the bit.ly posted links have been opened and requested the most, are some of the metrics you can use to find influentials for your business or startup.

Bit.ly offers a number of tools to track traffic, including Twitter search by subject that can show the most popular links, these can provide the raw data to find conversations around the bit.ly url.

PR and marketing firms are using Twitter to find the people who are most likely to re-tweet about their clients frequently, offering a Twitter hashtag. For example, when musicians book events, they often look for accounts with 5,000 or more followers in order to invite that whole group to the event. Tweetmeme.com provides a Twitter re-tweet plug-in you can add to Wordpress blogs that encourages viral spreading of posts. In conjunction with targeted blogger outreach, such tools can be effective at driving traffic of the right audiences to your business or brand.

The biggest challenge for a business that has an offline presence is finding local blogs and bloggers, and it can be done effectively using local geo-targeted directories such as Placeblogger , Outside.in , Everyblock.com , Twitter search and Globe of Blogs . The biggest cost is the time spent researching directories and building a local list of bloggers to invite.

An even more targeted hyper-local approach to finding the right audience for your business comes from a company called Fame Game , which tracked 150,000 of the most influential people and events happening in New York City over the last four years, and which has developed technology to drive targeted audiences to events by mapping and analyzing social connections and media attention. Individuals and organizations captured by Fame Game can claim the "profile" of their cultural footprint and actively affect it, both online and off.

While finding the right audience for your startup has always been challenging, it's never been easier to build one, as long as you're willing to invest time, track the results, modify your approach based on feedback and be patient.